Chapter 18-Blood

What is Blood?

A continuously regenerated connective tissue that transports gases, nutrients, wastes, and hormones.

What are the main parts of the cardiovascular system?

Heart (pumps blood), arteries (away from heart), veins (toward heart), capillaries (exchange).

What are the three main functions of blood?

Transportation, protection, and regulation.

What does blood transport?

Oxygen, carbon dioxide, nutrients, hormones, heat, and wastes.

How does blood protect the body?

Leukocytes fight pathogens; platelets and proteins prevent blood loss.

How does blood regulate body temperature?

Absorbs heat from cells and releases it at the skin.

Normal blood pH range?

7.35-7.45(slightly alkaline)

Average blood volume in adults?

About 5 liters (4–6 L range).

What is viscosity

Thickness of blood; blood is 4–5x thicker than water.

What are the two main components of blood?

Formed elements and plasma.

Name the formed elements.

Erythrocytes, leukocytes, platelets.

What makes up plasma?

92% water, 7% proteins, 1% solutes.

What is the buffy coat?

Thin middle layer of WBCs and platelets after centrifuging blood.

What is colloid osmotic pressure (COP)?

Pressure from plasma proteins that prevents fluid loss from blood.

Most abundant plasma protein?

albumin

Functions of globulins?

Transport molecules; gamma globulins act as antibodies.

Function of fibrinogen?

forms fibrin for blood clots

What is hemoglobin?

Red protein in RBCs that carries oxygen and carbon dioxide.

How many oxygen molecules can one hemoglobin carry?

four

What is hematocrit?

Percentage of RBCs in whole blood.

Normal hematocrit ranges?

Males 42–56%, females 38–46%.

What transports iron in blood?

transferrin

What stores iron?

ferritin

What is blood doping?

Increasing RBC count for athletic performance (illegal and dangerous).

What is diapedesis?

WBCs squeezing through blood vessel walls.

What is chemotaxis?

Movement of WBCs toward infection chemicals.

Most common leukocyte?

neutrophil

Neutrophils increase during what?

bacterial infections

Which leukocyte fights parasites and allergies?

eosinophil

Which leukocyte releases histamine?

basophil

What do monocytes become in tissues?

macrophages

Three types of lymphocytes?

T cells, B cells, NK cells

What is leukopenia?

low WBC count

What is leukocytosis?

high WBC count

What are platelets?

cell fragments that help blood clot

Normal platelet count?

150,000-400,000 per mm³

How long do platelets circulate?

8-10 days